Printed circuit board heat sink

Abstract

A heat sink for a printed circuit board in comprised of a thermally-conductive plate having on one surface a thermally-conductive, electrically-insulative elastomer layer which conformally engages at leasts a portion of the back surface of the printed circuit board. The ends of pins of electronic components mounted on the board and desired to be cooled embed into the elastomer layer to provide a conductive path for transfer of heat from the electronic components to the elastomer layer and then to the thermally-conductive plate.

What is claimed is: 
     
       1. A heat sink for cooling an electronic circuit formed of at least one electronic component having pins which attach the at least one electronic component to a printed circuit board and which protrude a short predetermined distance from the back surface of the board, comprising: a thermally-conductive plate having a firs planar surface;   a layer of a thermally-conductive, electrically-insulative elastomer disposed on the first planar surface of the plate, said layer of elastomer having a predetermined thickness greater than the short predetermined distance that the pins protrude from the back surface of the board; and   means disposed in combination with the plate and layer of elastomer for attaching the plate and the layer of elastomer to the back surface of the printed circuit board with the protruding portions of the pins of that at least one electronic component embedded totally within said elastomeric layer to provide a thermally-conductive path from the at least one component to said layer of elastomer for cooling the at least one electronic component, and wherein said layer of elastomer is sandwiched between the back surface of the printed circuit board and the first planar surface of the plate and conformally engages the back surface of the printed circuit board.   
     
     
       2. The apparatus of claim 1, wherein the area of the first planar surface of the thermally-conductive plate is substantially the same as that of the printed circuit board. 
     
     
       3. The apparatus of claim 1, wherein the thermally-conductive plate is aluminum, and the elastomer is silicone rubber. 
     
     
       4. The heat sink of claim 1 wherein the electronic circuit is formed of a plurality of electronic components and wherein said layer of thermally-conductive, electrically-insulative elastomer comprises individual elastomeric sheets having a size and configuration for embedding the protruding portions of the pins of respective ones of the plurality of electronic components to provide individual thermally-conductive paths from each of the plurality of electronic components to said respective elastomeric sheet for cooling the plurality of electronic components. 
     
     
       5. The heat sink of claim 4 wherein said thermally-conductive plate comprises a plurality of individual thermally-conductive plates wherein each of said plurality of individual thermally-conductive plates has a respective one of said individual elastomeric sheets disposed on said first planar surface thereof. 
     
     
       6. For use in a circuit board having one or more heat-generating electronic components mounted on one surface thereof, the components having pins which attach the one or more heat-generating electronic components to the circuit board and which protrude a short predetermined distance from the back surface of the circuit board, a heat sink for the circuit board, comprising: a thermally-conductive, electrically-insulative elastomer disposed on the back surface of the circuit board and having a predetermined thickness greater than the short predetermined distance that the pins protrude from the back surface of the circuit board wherein the protruding portion of the pins of at least one electronic component are embedded totally within said elastomer to provide a thermally-conductive path from the one or more heat-generating components to said elastomer for cooling the one or more heat-generating components;   a thermally-conductive plate disposed on the elastomer; and   means for securing the circuit board, said elastomer and said thermally-conductive plate together.   
     
     
       7. The heat sink of claim 6 wherein said thermally-conductive, electrically-insulative elastomer comprises individual elastomeric sheets having a size and configuration for embedding the protruding portions of the pins of respective ones of the one or more heat-generating components to provide individual thermally-conductive paths from each of the one or more heat-generating components to said respective elastomeric sheet for cooling the one or more heat-generating components. 
     
     
       8. The heat sink of claim 7 wherein said thermally-conductive plate comprises a plurality of individual thermally-conductive plates wherein each said individual elastomeric sheet has a respective one of said individual thermally-conductive plates disposed thereon.